Which diabetes complication involves high blood glucose with enough insulin to prevent ketone production?

• A. Dementia
• B. Hyperosmolar state
• C. Hyperosmolar hyperglycemic nonketotic syndrome (HHNS)
• D. Hypoglycemia

Answer: (C)

Nonketotic hyperosmolar hyperglycemic state occurs when blood glucose becomes extremely high but enough insulin is present to prevent lipolysis and ketone formation. The result is marked hyperglycemia with high serum osmolality and severe dehydration from osmotic diuresis, but without the metabolic acidosis that comes from ketone buildup. This combination—very high glucose, high osmolality, dehydration, and altered mental status without ketosis—is characteristic of hyperosmolar hyperglycemic nonketotic syndrome. The other options don’t fit: hypoglycemia is low blood sugar; dementia is not an acute metabolic crisis; while “hyperosmolar state” describes the osmotic part, the key feature here is the absence of ketosis, captured by the term HHNS.